How Much Do You Know About the Fiber Optic Cable?

What is fiber optic cable?

A fiber optic cable is a network cable that contains strands of glass fibers inside an insulated casing. These fiber optic cables are designed for long distance and very high bandwidth network communications. The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable will be deployed. Different types of cable are used for different applications, for example long distance telecommunication, or providing a high speed data connection between different parts of a building.

Fiber optic cables carry communication signals using pulses of light. While expensive, these cables are increasingly being used instead of traditional copper cables, because fiber offers more capacity and is less susceptible to electrical interference. So called Fiber To The Home (FTTH) installations are becoming more common as a way to bring ultra high speed Internet service to residences.

What are the color codes for fiber optic cable?

The fibers in optical fiber cables are numbered according to their color code, which simplifies connecting hardware installation and connector termination as well as further administration and testing of the cabling system.

fiber optic color code

The fibers are numbered in accordance with the individual standard color code given in figure 1. 250- and 900-micron buffer coatings are subject to color-coding. In modular design multifiber cables, the same color coding is applied with respect to modules.

In loose tube cables, with over 12 fibers in one tube, fibers can be combined to form a single unit fixed by colored threads.

In some cases to facilitate pair grouping the fibers are painted the same colors with collar marks every 2-3 cm (0.8 – 1.2 in) on the second fiber of the pair.

Colored outer jackets or print may be used on Premises Distribution Cable, Premises Interconnect Cable or Interconnect Cord, or Premises Breakout Cable to identify the classification and fiber sizes of the fiber.

When colored jackets are used to identify the type of fiber in cable containing only one fiber type, the colors shall be as indicated in Table 1. Other colors may be used providing that the print on the outer jacket identifies fiber classifications in accordance with subclause 4.3.3. Such colors should be as agreed upon between manufacturer and user.

Unless otherwise specified, the outer jacket of premises cable containing more than one fiber type shall use a printed legend to identify the quantities and types of fibers within the cable. Table 3 shows the preferred nomenclature for the various fiber types, for example “12 Fiber 8 x 50/125, 4 x 62.5/125.”

When the print on the outer jacket of premises cable is used to identify the types and classifications of the fiber, the nomenclature of Table 3 is preferred for the various fiber types. Distinctive print characters for other fiber types may be considered for addition to Table 1 at some future date.

fiber optic cable color code

Notes:

1. Natural jackets with colored tracers may be used instead of solid-color jackets.

2. Because of the limited number of applications for these fibers, print nomenclature are to be agreed upon between manufacturer and end-user.

3. Other colors may be used providing that the print on the outer jacket identifies fiber classifications.

4. For some premises cable functional types (e.g, plenum cables), colored jacketing material may not be available. Distinctive jacket colors for other fiber types may be considered for addition at some future date.

How does a fiber optic cable work?

To understand how a fiber optic cable works, imagine an immensely long drinking straw or flexible plastic pipe. For example, imagine a pipe that is several miles long. Now imagine that the inside surface of the pipe has been coated with a perfect mirror. Now imagine that you are looking into one end of the pipe. Several miles away at the other end a friend turns on a flashlight and shines it into the pipe. Because the interior of the pipe is a perfect mirror, the flashlight’s light will reflect off the sides of the pipe (even though the pipe may curve and twist) and you will see it at the other end. If your friends were to turn the flashlight on and off in a morse code fashion, your friend could communicate with you through the pipe. That is the essence of a fiber optic cable.

Transmitter

A transmitter is a device found at the beginning of a fiber optic cable network. The transmitter takes information and turns it into a pulsing light wave that can be sent along a fiber optic cable. A lens is then used to send the light into a fiber optic cable. The light will travel along the fiber optic cables more quickly and with less signal degradation than occurs when sending data along traditional coper wires.

Fiber Optic Cable

The core of a fiber optic cable is made of a very clear glass tube that transmits light. This glass core is surrounded by a coating called cladding. Light will travel down the fiber optic tube in a straight line. Unfortunately, not all fiber optical cables can be laid along a straight path, so the cladding surrounding the cable is mirrored. The light bounces off of the mirrors on the cladding and is directed back into the fiber optic core to continue its journey along the cable.

Optical Regenerator

Sometimes a light signal must travel through a fiber optic cable over a very long distance. Although signal degradation is minimal in a fiber optic cable, some degradation does occur. When a cable covers a long distance, optical regenerators are placed at certain intervals along the cable. Optical regenerators are fibers that have been treated with a laser. The molecules in the fiber allow the signal traveling through the fiber optic cable to take on laser properties themselves, which strengthens the light signal. Optical regenerators essentially strengthen the light signal that is traveling through a fiber optic cable.

Optical Receiver

At the end of the fiber otic network there is an optical receiver. This receiver is essentially performs the opposite function of the transmitter found at the beginning of the system. Optical receivers receive the light signal from the fiber optic cable and turn it back into information that a computer or television know how to understand and use. It then sends the decoded signal to the computer or television.

Types of loose tube fiber optic cables

FiberStore have many types of loose tube fiber optic cables, such as All -Dielectric Loose Tube Cables, Gel-Filled Loose Tube Cables, Double-Jacket Loose Tube Cables, Central Loose Tube Cables.

Guide To Choose The Best Fiber Optic Cable Suits Your Application

Fiber optic cable is favored for today’s high-speed data communications because it eliminates the problems of twisted-pair cable, such as near-end crosstalk (NEXT), electromagnetic interference (EMI), and security breaches. Fibre Optic Cable is the preferred option in the interconnecting links between floors or buildings, is the backbone of any structured cabling solution. While, making the right decisions when it comes to Data Network cabling is difficult as it can make a huge difference in the ability of your network to reliably support current and future requirements. There are many factors to consider and today I will guide you through the many options available and find the best one suits your application.

1. Multimode Fiber Cable Or Single-mode Fiber Cable

There are two basic types of fiber: mulitimode and single-mode. Both types consist of two basic components: the core and the cladding which traps the light in the core.

Multimode fiber cable

Multimode fiber, as the name suggests, permits the signal to travel in multiple modes, or pathways, along the inside of the glass strand or core. It is available with fiber core diameters of 62.5 and a slightly smaller 50 microns. The problem with multimode fiber optics is that long cable runs in multiple paths may lead to signal distortion. This can result in incomplete and unclear data transmission.

Applications covering short distances can use multimode fiber optic network cable. Ideal uses for such kinds of cables are within data center connections. Multimode cables are economical choices for such applications. There are various performance levels within the multimode fiber optic cable such as OM3 cable for distances within 300 m, OM4 cable supports Gigabit Ethernet distances within 550m and 10G applications.

Single-mode fiber cable

Single-mode fiber cables offer a higher transmission rate. These cables contain a tiny core that measures about five to ten microns. These tiny cores have the capacity to eliminate distortion and produce the highest transmission speeds. Single-mode fiber generally has a core that is 8.3 microns in diameter. Singlemode fiber requires laser technology for sending and receiving data. Although a laser is used, light in a single-mode fiber also refracts off the fiber cladding. The presence of high intensity lasers helps transfer data across large distances. Singlemode has the ability to carry a signal for miles.

Single mode is used for long haul or extreme bandwidth applications, gives you a higher transmission rate and up to 50 times more distance than multimode, but it also costs more. The small core and its single lightwave virtually eliminate any distortion that could result from overlapping light pulses, providing the least signal attenuation and highest transmission speeds of any fiber cable type.

The best choice to choose multimode optical cable when the transmission distance is less than 2km. In the other sides, use single-mode optical cable when the transmission is more than 2km. Although the core sizes of multimode and singlemode fiber differ, after the cladding and another layer for durability are applied, both fiber types end up with an outer diameter of about 250 microns. This makes it both more robust and easier to work with.

2. Indoor Cable Or Outdoor Cable

The major difference between indoor and outdoor cables is water blocking. Any conduit is someday likely to get moisture in it. Outdoor cables are designed to protect the fibers from years of exposure to moisture.

Indoor Cables

Indoor cables are what we call “tight-buffered” cables, where the glass fiber has a primary coating and secondary buffer coatings that enlarge each fiber to 900 microns—about 1mm or 1/25-inch—to make the fiber easier to work with. Indoor cables are flexible, and tough, containing multiple Tight Buffered or Unit Cord fibers.

Types Of Indoor cables available

indoor cables

Simplex and Zip Cord: Simplex Fiber Optic Cables are one fiber, tight-buffered (coated with a 900 micron buffer over the primary buffer coating) with Kevlar (aramid fiber) strength members and jacketed for indoor use. The jacket is usually 3mm (1/8 in.) diameter. Zipcord is simply two of these joined with a thin web. It’s used mostly for patch cord and backplane applications, but zipcord can also be used for desktop connections. They are commonly used in patch cord and backplane applications. Additionally, they can be utilized for desktop connections. These cables only have one fiber and are generally used indoors.

Distribution cables: They contain several tight-buffered fibers bundled under the same jacket with Kevlar strength members and sometimes fiberglass rod reinforcement to stiffen the cable and prevent kinking. These cables are small in size, and used for short, dry conduit runs, riser and plenum applications. The fibers are double buffered and can be directly terminated, but because their fibers are not individually reinforced, these cables need to be broken out with a “breakout box” or terminated inside a patch panel or junction box. The distribution cable is smaller and used in dry and short conduit runs, plenum and riser applications, is the most popular cable for indoor use.

Breakout cables: They are made of several simplex cables bundled together inside a common jacket for convenience in pulling and ruggedness. This is a strong, rugged design, but is larger and more expensive than the distribution cables. It is suitable for conduit runs, riser and plenum applications, is ideal for industrial applications where ruggedness is important or in a location where only one or two pieces of equipment (such as local hubs) need to be connected.

Outdoor Cables

Optical fiber in outdoor applications requires more protection from water ingress, vermin, and other conditions encountered underground. Outdoor cables also need increased strength for greater pulling distances. Buyers should know the potential hazards that the cables will face, for example, if the cables will be exposed to chemicals or extreme temperatures.

Loose Tube cables: These cables are composed of several fibers together inside a small plastic tube, which are in turn wound around a central strength member and jacketed, providing a small, high fiber count cable. This type of cable is ideal for outside plant trunking applications, as it can be made with loose tubes filled with gel or water absorbent powder to prevent harm to the fibers from water. Since the fibers have only a thin buffer coating, they must be carefully handled and protected to prevent damage. It can be used in conduits, strung overhead or buried directly into the ground.

Ribbon Cable: This cable offers the highest packing density, since all the fibers are laid out in rows, typically of 12 fibers, and laid on top of each other. This way 144 fibers only has a cross section of about 1/4 inch or 6mm! Some cable designs use a “slotted core” with up to 6 of these 144 fiber ribbon assemblies for 864 fibers in one cable! Since it’s outside plant cable, it’s gel-filled for water blocking.

Armored Cable: Cable installed by direct burial in areas where rodents are a problem usually have metal armored between two jackets to prevent rodent penetration. This means the cable is conductive, so it must be grounded properly. You’d better choose armored fiber cable when use cable directly buried outdoor.

Aerial Cable: They can be lashed to a messenger or another cable (common in CATV) or have metal or aramid strength members to make them self supporting. Aerial cables are for outside installation on poles.

The table below summarizes the choices, applications and advantages of each.

Cable Type Application Advantages
Distribution Premises Small size for lots of fibers, inexpensive
Breakout Premises Rugged, easy to terminate, no hardware needed
Loose Tube Outside Plant Rugged, gel or dry water-blocking
Armored Outside Plant Prevents rodent damage
Ribbon Outside Plant Highest fiber count for small size

All cables share some common characteristics. For example, they all include various plastic coatings to protect the fiber, from the buffer coating on the fiber itself to the outside jacket. All also include some strength members for pulling the cable without harming the fibers. Outdoor fiber optic cable has moisture protection, either a gel filling or a dry powder or tape. Direct-buried cables may have a layer of metal armor to prevent damage from rodents. It is advisable that you should customize your cable to make it suitable to your application when the quantity of fiber optic cables is large and also for the cost-effective reasons. Knowing basic information about fiber optic cables make choosing the right one for the project a lot easier. It is always beneficial to konw more about fiber optic cables.

How Do Fiber Optics and Cable Television Work

Fiber optical cable and the old common (RF or coaxial) cabke are two different cable system technologies that can be used to distribute various services to end users-homes. In general, they differ only in technical (electrical or communication) point of view. This is mainly important for the network operators because end users or viewers don’t care about the technology, they are insterested in services and TV channels.

There are serveral different methods that can be used to release public services like television channel through a cable television network. Each has some advantages and disadvantages and require different topology structure and network infrastructure.

Analog Television

The first cable television network was just extension of the broadcast in the air. This was implemented by deploying ordinary antenna cable (but with lower losses) from the cable system headend to the homes. Because of distance and many amplifier at a particular point, to ensure that the required signal level. Special communication is one-way, but then most of these cable network to expand to DocSys allows two-way communication need to access the Internet through the use of the system.

This approach can be used with radio frequency coaxial and optical fiber cable. Fiber optic cables are also used in some cases to distribute the old analog cable television. The advantage of optical network because it can use the available fiber in the existing optical fiber cable and the cable loss is very low.

Digital Television

Digital television in cable networks can be divided into two totally different ways of distribution. The first one is an equivalent to digital broadcasting and the other way mainly used in fiber optic networks is IP television.

Digital Cable Broadcastingn

This is equivalent to analog distribution over (RF) cable but with digital signal. The same technology (modulation) can be used as the ground broadcasting but usually, there are more efficient systems, considering the specific properties of the cable system. One typical example is DVB-T system which is used in Europe for digital terrestrial video broadcasting but cables use similar DVB-C system.

IP Television

This is one of the most popular digital television distribution used with fiber optic cable systems. This means that the distribution channels with IP protocol is the backbone of network communication. Each TV channels is encoded with either MPEG-2 or MPEG-4 system and then distributed over fiber optical cable network to the homes. The advantages are enormous. The capacity for the number of channels is pretty high, all the channles can be encoded and distributed with very high quality, it is very easy to distribute HD channels, access to the internet is very simple because of the IP protocol and native technology.

Regardless of distribution cable technology the changes are also happening in the consumer industry. The old CRT television sets are replaced by plasma or LCD flat panel displays and aspect ratio or picture format is also changing from 4:3 to 16:9. Since computer LCD monitors use similar display panels they can be converted to televisions by just adding a simple TV tuner.

How To Successful Installation of Underground Fiber Optic Cable

The two most common outdoor fiber optic cable installations are pole line aerial installation and underground cable installation. Underground cable installation can be directly buried underground or in a buried pipe.

Direct burial installation

Direct burial installations are most common for long cross country installations. The cables are plowed in or buried in a trench; the installation process can be very fast. The most common type of cable is used in the directly buried cables is outdoor steel armor.

Underground duct installation

Fiber optic cables can also be pulled through underground ducts, which protect the cables from harsh environment. Underground duct installation also provides opportunity for future expansion without the need to dig. This is the most common approach in urban areas. Another benefit is that the fiber optic cable no armor can be used to make installation easier.

Preparation before underground cable installation

1. The right to receive appropriate one-way permits

2. Identify existing underground utilities such as buried cables, pipes

3. Investigate the soil condition in order to determine the installation depth, whether duct should be used, the type of fiber cable should be used and plowing equipment needed.

Buried cable technology

1. Plowed under

Cultivated land is faster than cuts in the fiber optic cable. But the process must be carefully monitored to prevent damag to the cable.

2. Trenched

Fiber optic cable can also be cut. This process is slower than farming; however, it allows a more control cable installation. Dig trenches can by hand or by machine.

3. Directional boring

Directional boring technique is used where the surface cannot be engaged in such as high, the railway crossing. On the contrary, a drilling machine is used to bore a few inches beneath the surface of the hole diameter, a pipe is out of the mouth of the cave, and then dragged into fiber optic cable pipe.

Important factors

1. Cable installation depth: up to 40 inches

The depth that fiber cables should be buried is determined by the soil conditions and surface usage. In cold region, fiber optic cable is buried below the frost line, usually prevent damage of cable is the ground frost.

2. Keep the trenches as straight as possible

Fiber cable trenches should be straight, and should be formed at the bottom of the trench. Backfill soil could also be used to load evenly distribution cable and protect the cable.

3. Fiber cable warning labels should be buried directly above the cable

Fiber optic warning cables are typically buried directly above the cables to warn future digging operations. Or concrete slabs can be buried below the warning label but above the cables to provide even more protection.

4. Whenever armor fiber cable used, they should be properly grounded

In the directly buried installations, steel armored fiber optic cable is often choose for their strength and protection from rodents bite. A very important thing to remember is proper grounding cable. They should be down-to-earth in all end points, splicing and the entrance of the building. Steel armored cable should be connected to ground using compression type clip. Cable near ground is then bolted to the ground terminal strip.

5. Fiber optic cable minimum bending radius should always be observed during installation.